Charging system fault?
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5th Gear
Joined: Feb 2017
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Charging system fault?
The other day I was driving and got a random check engine light, then it came back off. Today happend again along with charging system fault? My car is having trouble starting and my battery gauge says it's at 9.7. When I'm driving sometimes it goes back up to 12.0 volts but yeah. Where to start?
Tech Contributor
Joined: Dec 1999
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
weak or bad battery, bad/corroded connections at the battery or the positive connection to the starter solenoid, burned wires on the starter solenoid (especially if the car has headers), loose connection at the starter solenoid, burned contacts in the ignition switch would ALL be things to start checking.
Use a digital multimeter to measure voltage at the battery posts. A good battery at full charge will measure 12.7 to 12.9 volts or more directly across the battery posts.
Dash gauges do NOT report the state of health of the battery but rather the state of health of the charging system. Further since those gauges are downstream of the ignition switch, burned or carboned up ignition switch contacts can result in voltage drops across the ignition switch preventing the true charging voltage from being reported...... Once again use a digital multi meter. Measure the output voltage at the alternator (should be 14+ volts) and again at the battery posts. BOTH those readings should be within 0.1 or so volts of one another. If not then the connections at the starter solenoid are HIGHLY suspect. Dash gauge readings are notoriously inaccurate on a C5 because of the ignition switch.
Use this link to diagnose the ignition switch:
diagnosis
http://forums.corvetteforum.com/1568186703-post64.html
Voltage readings at the fuses indicated in the above link should be within about 0.2 or 0.3 volts of the battery voltage. If not then the ignition switch is highly suspect.
Use a digital multimeter to measure voltage at the battery posts. A good battery at full charge will measure 12.7 to 12.9 volts or more directly across the battery posts.
Dash gauges do NOT report the state of health of the battery but rather the state of health of the charging system. Further since those gauges are downstream of the ignition switch, burned or carboned up ignition switch contacts can result in voltage drops across the ignition switch preventing the true charging voltage from being reported...... Once again use a digital multi meter. Measure the output voltage at the alternator (should be 14+ volts) and again at the battery posts. BOTH those readings should be within 0.1 or so volts of one another. If not then the connections at the starter solenoid are HIGHLY suspect. Dash gauge readings are notoriously inaccurate on a C5 because of the ignition switch.
Use this link to diagnose the ignition switch:
diagnosis
http://forums.corvetteforum.com/1568186703-post64.html
Voltage readings at the fuses indicated in the above link should be within about 0.2 or 0.3 volts of the battery voltage. If not then the ignition switch is highly suspect.
100%
BC
